The researchers also looked at resistance to oseltamivir-based agents (Tamiflu is the brand name for oseltamivir phosphate), but found that fewer than 1 percent of all of the samples were resistant to that class of drugs. Different classes of antivirals target influenza in different ways in the hosts' cells.
Janies and researchers from the University of Colorado and Kansas State University also designed a four-dimensional interactive map that traces the resistant avian flu lineages, showing over time where they originated and where they moved, mostly across Asia, but also to one European site in Belgium. The map is projected onto a virtual globe using Google Earth and can be downloaded at: http://supramap.osu.edu/supramap/files/h5n1_677.kmz.
The study is published online in the journal Infection, Genetics and Evolution.
So far, avian flu, the H5N1 strain of the influenza A virus, has been restricted to fewer than 400 human cases worldwide, but the virus's presence in birds has led to culling of large populations of infected species. Experts believe that to date, the avian flu can be transmitted to humans only from diseased birds. But the 63-percent death rate among the humans who had the virus has led to global concerns that if H5N1 were to become highly transmissible among humans, it could start an influenza pandemic.
Janies and colleagues obtained 676 whole genomes of influenza A/H5N1 available in Genbank, a public database of sequences supported by the National Institutes of Health, as of June 2007. They then used powerful supercomputers to analyze these genomes and their various mutations.
Adamantanes fight influenza by inhibiting the function of a p
|Contact: Daniel Janies|
Ohio State University